By mile 10 of my first half-marathon, the persistent, frigid drizzle had forced my fingers into a clenched C shape. The thrill of running alongside thousands of people after weeks of solo training had mellowed into a quiet, somewhat dull drive toward the finish line. Then, without warning or conscious effort, my body started moving faster. The hard pavement felt like a supportive mattress. A sense of elegance freed me from my clumsy body. I was — there is no other way to put it — at one with the cityscape around me. I was in the zone.